False twist spindle



Nov. 8, 1966 W. v. GOODHUE FALSE TWIST SPINDLE Filed Feb. 2, 1965 lN e o l un W.

Ju w l Il W, IHHH'MHY 22V 3,283,490 FALSE TWIST SPINDLE William V. Goodhue, North Kingstown, RJ., assignor to Leesona Corporation, Warwick, RJ., a corporation of Massachusetts Filed Feb. 2, 1965, Ser. No. 429,824 6 Claims. (Cl. 57-77.33)

The present invention is concerned with textile machinery and, more particularly, with false twist spindles.

In recent years, crimped synthetic yarns have found widespread consumer acceptance. The process most often used for imparting the crimped structure to the yarn involves twisting the yarn, setting the twist, and untwisting the set yarn in a continuous, uninterrupted operation. Such processes are most commonly carried out through the use of so-called false twist spindles. In general, such false twist spindles each comprise a rotating body having an axial channel therein through which the yarn is passed, and a yarn engaging means which is attached to and rotates with the body and which serves to prevent free twist migration of the yarn. Usually the yarn engaging means comprises a looping means around which the yarn may be looped as it is drawn through the spin dle. A simple pin positioned across the path of the yarn through the spindle and around which the yarn may be looped for one or more complete turns has been found particularly useful. Such a pin is commonly referred to as a twist trapping pin.

In operating the false twist spindles, it is desir-able that they rotate at high speeds, e.g., at least 50,000 r.p.m., in order to impart as many twists as possible per inch to the yarn. Suitable spindles of this type are known such, for example, as those taught in U.S. Patent No. 3,044,247 to Richard G. Hilbert, which have special bearings and lubricating systems which accommodate speeds of at least 150,000 r.p.m. Although the false twist spindles, which have been available up to the present time, have provided satisfactory results, it has been found that undesirable breaks in the yarn sometimes occur, necessitating the shutting down of the equipment. The present invention is concerned with providing improved false twist spindles which substantially reduce the number of breaks which occur in the yarn during the crimping process.

One object of the present invention is toprovide improved false twist spindles.

Another object of the present invention is to provide improved high speed false twist spindles which substantially reduce yarn breakage during use.

A further object of the present invention is to provide an improved false twist spindle provided with a novel twist trapping pin configured to arrest twist migration in the yarn to a high degree of effectiveness.

Other objects and advantages will be apparent from the following detailed description of illustrative embodiments of the invention when read in conjunction with the accompanying drawings in which:

FIGURE 1 is an enlarged detailed view of a false twist spindle of the present invention, partly in vertical cross section;

FIG. 2 is a top view of the yarn engaging means of the present invention;

FIG. 3 is a vertical cross-sectional view of the yarn engaging means of the present invention along lines III-III of FIG. 2; and

FIG. 4 is a view similar to FIG. 3 illustrating a modied form of the invention.

It has been found, in the present invention, that a substantial reduction in the number of shut-downs due to yarn breakage may be made by providing a continuous United States Patent O ICC channel on the yarn engaging means to hold the yarn and define the yarn path on said means. The invention has been found particularly useful in false twist spindles employing twist trapping pins as the yarn engaging means. In such spindles, a simple, continuous, helical channel around the pin has been found quite useful in cutting down the number of breakdowns. Apparently such channels exert a positive hold on the yarns and prevent them from binding or abrading on themselves at the high speeds at which the spindles are rotated. Moreover, by virtue of the present invention a twist trapping pin is provided which has a V-shaped helical groove. Thus, the yarn is wedged into the groove as it passes through the spindle. Hence, whereas in prior art spindles it was to accept substantially full wraps of yarn, i.e., approximately 360 `of engagement between the yarn and the twisting trapping pin, or some general multiple of 360, in practice with the present invention intermediate values can be attained. That is to say, by the simple expedient of opening or closing the angularity of the opposing side walls of the V-shaped helical groove a wedging condition provided thereby acting on the yarn can produce a gripping contact more effective than, say, 360 of yarn wrap.

If it be assumed, let us say, that 540 of wrap contact between the yarn and the surface of a cylindrical prior art twist trapping pin would provide the optimum twist trapping condition for a given yarn, obviously, this value of 540 could not be achieved in the prior art since, as already stated, the yarn would have to be wrapped on such pins for one or more substantially full turns. Thus, in the past it would have been necessary to accept some compromise at either a wrap angle of approximately 360 or, in the alternative, about 720. In contradistinction thereto, the present invention admits of providing, by means of a V-groove, an effective gripping force which can be equated to a wide variety of wrap angles. This is attributable to the wedging effect of the yarn in the V-shaped groove formed around the periphery of the twist trapping pin.

In general, the false twist spindles of the present invention comprise a rotatable body, means for rotating said body, a channel in the rotatable body through which the yarn is passed and a yarn engaging means attached to and rotatable with the body; the yarn engaging means having a continuous channel thereon defining the path the yarn follows around the engaging means when the spindle is in operation.

In FIGS. 1 through 3 there is shown a preferred embodiment of the present invention in combination with a high speed false twist spindle, such as disclosed in the above-mentioned U.S. Patent No. 3,044,247. The spindle 10 shown in FIGURE 1 consists essentially of a spindle blade 12, a housing 14 Yand journals or bearings 16 in the housing for engaging the ends 52a and 52b of the spindle blade 12. The housing 14 is a C-shaped metal block having a thick flat back portion 1S and a pair of legs 20a and 20b extending from the ends of the back portion 18. Each of the legs 20a and 2017 has, passing therethrough, coaxial, equal-diameter, cylindrical bores 22a and 22b, whose axes are parallel to the plane of the back portion 18.

Each of the bores 22a and 2217 is adapted to receive a cylindrical, plug-like bearing rnount 24, fabricated fnom a porous material such as sintered bronze through which oil may permeate. The two :bearing mounts 24 are substantially identical in configuration and have diameters slightly less than the diameters Iof bores 22a and 22b to facilitate their insertion therein. The bearing mounts 24 are held in the bores 22a and 22h on the inside ends, i.e.,

the ends closest to the spindle bla-de 12, by split retaining rings 26 and on the outer ends by bowed or dished retaining rings 30.- Between the retaining rings 26 and 30 and the bearing mounts 24, annular spacing washers 28 and 32, respectively, are disposed which serve to shield the mounts 24 from dust a-nd the like. The retaining rings 26 and 30 engage internal grooves 33 and 34, respectively, which are provided for that purpose in the walls of the bores 22a and 2lb. In order t-o insure proper radial alignment of the bearing mounts 24 there is provided a small cylindrical passage 36 which extends transversely to the axis of the Ibores 22a and 22h and through the annular walls of each of the legs 20a and 20b. Through these transverse passages 36, positioning pins 38 are inserted until the internal ends of the pin 38 engage a recess 40 provided in the outer surface of each bearing mount 24.

Each bearing mount 24 has a small central axially directed bore 42 which is coaxial with bores 22a and 22b and which has internal ends 44 which flare outwardly at a relatively large acute angle. Two substantially identical radially extending channels or slots 46, positioned at about an arc of 90 from one another,-are cut from the central bore 42 into each mount 24 (only one slot 46 is shown for each mou-nt 24). The `slots 46 extend radially into the mount 24 for about half the radial thickness of the mount 24 and extend longitudinally for about the full length of the small bores 42. At the back end of each slot 46 there is positioned a metal plate 48 which is roughly coter-minous with each slot. On top of the plates 48 are inserted wear-resistant bearing mounts 51 or journals which extend a small distance into the central bore 42.

The spindle blade 12 is of generally elongated cyl-V indrical configuration having an axial bore 50 extending through the full length thereof for passage of the yarn, the lower end of the bore being ared. Adjacent each end, the diameter of the blade is substantially reduced as compared to its normal diameter, the reduced end portions 52a and 52b serving as bearing surfaces for the spindle 12while the mid-portion 54 functions as a whorl. At the transition of the mid-portion 54 to each end portion 52a and 52h is a shoulder 56 tapering at an angle roughly complementary to the angle of the dared internal ends 44 of the bores 42.` The mid-portion 54 of the spindle 12 engages an endless belt 58 which serves as a drive means. The endless belt is positioned opposite the journals 51 and a small amount of lateral free play is provided between the reduced end portions 52a and 52b of the spindle 12 and the central =bores42 so that during use the end 52a and 52b and shoulderr 56 portions will be forced against the bearing surfaces of the journal 51 1and away from the walls of the central bore, thus causing the journals S1 to bear the -brunt of the load.

A yarn engaging unit 60 is attached to the top end portion 52a of the spindle 12. In general the yarn engaging means Vcomprises a cylindrical coupler 62 which is ixedly attached to the top end 52a of the spindle. The coupler has a lbore y64 therein which leads into and is coaxial with `the bore 50 of the spindle. A twist trapping pin 66 is attached -by its ends to the walls of the cylindrical coupler and traverses the bore 64.- The trapping pin 66 which is generally cylindrical in shapeis, as shown, xedly attached to the coupler. A V-shaped, helical channel or groove 68 which is adapted to receive the yarn is cut into the cylindrical surface of the trapping .pinY

66. The length of the ygroove -68 may be varied depending upon the number of times it is ldesired to loop `the yarn around the trapping pin 66. Generally the .groove 68 is of sucient depth to hold the yarn in place and prevent it from sliding along the pin 66 and binding and` locking upon itself. The pin 66, in preferred embodiments, is pitched so as to intersect the axis of the bore 64 at an angle of less than 90, e.g., about 50 to 80 and conforming with the helix angle of groove 68.

A yarn guide 70 is positioned above the yarn engaging unit -60 to prevent the yarn from ballooning as it leaves the false twist spindle. In general the yarn guide 70 comprises a length of stiff wire 72 having a small loop 74 at its upper end which is coaxial with the bore 50 lof the spindle 12 and serves as the yarn guide, anda large loop 76 at its lower end by means of which it is attached to the housing 14 of the false twist spindle 10.

In high speed false twist spindles such as shown `in FIGURE l, the rotating members'cannot come into direct contact with the lubricantA which, at such speeds, would have a retarding effect on spindle rotation. Lubrication is accomplished by providing an annular recess 78 in each of the 'bores 22a and 22b. The recesses 78 extend into the legs 20a and 20h, and are in communication with an oil reservoir 80 which is filled with oil absorbent felt 82. The felt serves t-o retard the ow of oil through the porous bearing mount 24 and prevents over-lubrication. Oil may :be supplied to the reservoirs 80 by passageways 84 and 86, and access to the reservoir 80 may be had through cap 88. During use a sufficient amount of oil or oil vapors is supplied to the rotating members through the porous bearing mount 24 to provide adequate lubrication.

In using the false twist spindle 10 of the present invention, the yarn Y, from any suitable supply package (not shown) is passed through the bore 50 ofthe spindle 12, around the twist trapping pin 66, lfollowing the helical groove 68, and through the yarn guide 74 `to any suitable take-up `mechanism (not shown).

In FIG. 4 there is illustrated a modification of the invention wherein a yarn engaging unit 60 is provided with horizontally aligned bores 61,1 61' into which a twist trapping pin 66 is xedly seated as by ibeing cemented therein. The twist trapping pin 66" spans bore 64 and intersects the axis thereof at an angle of A V- shaped helical groove 68 is cut in the cylindrical surface of pin 66. The length of the groove may be varied depending on the num-ber 4of wraps the yarn Y will make about the pin.

In both the embodiments disclosed herein it will be apparent that the angularity of the groove may be formed to any desired value and the groove may be of any de-l sired depth in order that a V-belt or wedging elfect of any desired degree may be attained on the yarn. Howt ever, the groove opening should be of sufcient width to seat or receive the yarn so that the yarn would be incapable of jumpingout of the groove as it is pulled yarns comprising, a rotatable member having an axial` bore therethrough for the passage of yarns, means for mounting said member yfor rotation, a yarn engaging element connected with said member and arranged to engage the yarn passing through said axial bore to' rotate4 the yarn, and a helical groove formed in the surface .of said element for receiving said yarn whereby to define a helical path for said yarn as the yarn engages said element.

2. A false twist spindle as set forth in claim 1 wherein the opposing sides of said helical groove are inclined lto form a V-shaped groove in cross-section.

3. A false twist spindle as set forth in claim 1 wherein said helical groove extends around said element through a path of at last 360.

4. A false twist spindle as set forth in claim 1 wherein References Cited by the Examiner said element spans said axial bore, said element being UNITED STATES PATENTS xed agamst rotation on lts own axis for shding passage of the yam therepast. Klell'l 5. A false twist spindle as set lforth in claim 1 wherein 5 3,044,247 7/ 1962 Hilbert 57-77.45 said yarn engaging element is arranged with its axis at 3,161,706 12/ 1964 Peters 57-77.4X an angle of less than 90 to the axis of said rotatable 3,180,074 4/ 1965 Smith 57-77.33

member.

6. A false twist spindle as set forth in claim 1 wherein FRANK I- COHEN, Primary Examiner said yarn engaging element is arranged with its axis nor- 10 D E. WATKINSI Assistant Examiner. mal to the axis of said rotatable member. 

1. A FALSE TWIST SPINDLE FOR TWISTING AND UNTWISTING YARNS COMPRISING, A ROTATABLE MEMBER HAVING AN AXIAL BORE THERETHROUGH FOR THE PASSAGE OF YARNS, MEANS FOR MOUNTING SAID MEMBER FOR ROTATION, A YARN ENGAGING ELEMENT CONNECTED WITH SAID MEMBER AND ARRANGED TO ENGAGE THE YARN PASSING THROUGH SAID AXIAL BORE TO ROTATE 